Device for regulating the amount of fuel delivered to injection internal combustion engines



1941- A. SCHWEIZER Er AL 33,035

DEVICE FOR REGULATING THE AMOUNT OF FUEL DELIVERED TO INJECTION INTERNALCOMBUSTION ENGINES Filed July 21, 1957 2 sheefssheet 1 Feb. 1941- A.scu'wsxzz EIAL 33.035

DEVICE FOR REGULATING THE AMOUNT OF FUEL DELIVERED T0 INJECTION INTERNALCOMBUSTION ENGINES Filed July 21, 1937 2 sheetsesheet 2 45 fulfil verydefinite regulating demands, remain ber formed by the plunger isconnected by a flexi- 45 Patented Feb. 1941 UNITED STATES PATENT oFFicEDEVICE FOR REGULATING THE AMOIlN'l' or FUEL DELIVERED T .INJEo'rIoNINTER- m1. COMBUSTION ENGINES Alfred Schweizer and Max Hurst, Stuttgart,Germany, assignors to Robert Bosch Gesellschai't mit beschriinkterBattling, Stuttgart, Germany Application .mn' 21, 1937, Serial No.154,86 In Germany July 10, 1936 9 Claims. (01. 123-140) vThe presentinvention, relates to devices for to both members, and are subject tothe playof regulating the amount of fuel delivered to injecthe forcesoperating on both members, but which tion internal combustion engineswhich work at do not transmit to one member the forces operatconstantand also at sharply changing external ing on the other but only transmitsaid forces to air pressure. The device consists of a pneumatic themember of the injection pump adjusting the 5 regulatorwhich actuatesthemember of the in-', amount. jectionapparatus adjusting the amountdelivered; The invention is more particularly described the regulatingmember of this regulator is adjustwith reierence to the accompanyingdrawings in ed' on one hand by the difference between the which severalforms of construction are shown.

pneumatic pressure drop, which operates on the In these drawings Fig. 1shows in partial longi- 10 regulating member (between the atmospherictudinal section an injection pump having a built pressure and thepressure in the air supply pipe) on ,regulator and also a memberresponsive to and aretum force which operates counter to'the variationsin atmospheric pressure. Fig. 2 is a pressure drop in the "whole rangeof speeds, and similar view of a modified arrangement with a on theother hand by a barometer operating member limiting the adjustment ofthe regulator. mechanism responsive to variations in atmos- Fig. 3 showsa further form of construction. Fig. pheric pressure. With changingexternalair 4 shows a still further example of construction. pressurethe adjustment of the pneumatic r'egu- In the drawings the casing of aninjection pump lator alters, as does the weight of the quantity is shownat l, the cam shaft at 2 and the pump of air sucked in bythe cylinders.piston at 3, The pump pistons-3 are adjusted ro- 20.

In its operation on the member of the pump adtatably about their axesbymeans of a toothed justing the amount delivered, and consequently oncontrol rodv 4, whereby the-position of an oblique the exactproportioning of the amount injected, control edge on each piston isaltered in relation v the-pneumaticregulator has functions to fulfil into the return opening to control the amount of which it may besupported, but not hindered, by fuel-delivered to the engine by eachpiston. The 25 the barometric regulation of the amountinjected fuel tobe injected to a nozzle of the internal on alterations in atmosphericpressure. If the combustion machine '(not shown) is delivered barometerwere to be coupled with the pneumatic through a pipe 5. Thecontrol rod 4projects into regulatorand with the member of the pump ada casing 6builton the injection pump; this cas- 3 justing the amount delivered insuch a' manner ing'is open at the end remote from the pump and that, forinstance the adjustments of the baromits inner chamber 6' is incommunication with ateter. consequent on alterations in external air.mosphere by openings II. A hollow plunger 9 Pressure. resulted in acertain alteration of the having a radialwall at one. end and enclosinga return force of the pneumatic'regulator, then a regulating chamber isinserted in the casing 6;

return pressure would beexercised on the baromthis sleeve is completelyclosed at its opposite end 35 1 x which ld soon destroy-it- By h by abent diaphragm 8 stretched between plates present invention e barometerand the pneu- 1, the outer edge of the diaphragm being tightly maticregulator may be arranged in relation to secured to th plunger 9, Thdiaphragm i the member of the'injection pump adjusting the nected'by theplates I with the free end of the 40 amount delivered, and the directand indirect incontrol rod.

fluence of the alterations in the atmosphericfpres- The plunger 9 isarranged in the guide casing sure on the pneumatic regulator may be bal-6, so 'as tobe movable longitudinally of its axis, anced, while at thesame time the internal forces and as a closed unit is displaceable'either with of adjustment of the pneumatic regulator, which the controlrod or relative to it; The inner chamuninfiuenced by the barometricregulation; also, ble pipe 10 with the space situated behind theconversely, an adjustment of the pneumatic reguthrottle valve l3 in'theinduction pipe l2 of the lator does not, as a consequence, transmit itsadengine. The flexible pipe l0 which is firmly conjusting force to thebarometer. nected with the plunger 9 passes through a slot The inventionlies in the fact that both the It in the casing 6 is of sufficientlengthto enable 50 members which regulate the delivery amount of it to stretchto the limiting position of the plunger the injection pump, thebarometer and the pneuremote from the induction pipe. One end of arematic regulator, operate on the memberof the inturnfspring l5 abuts onthe radial end H; of the jection pump controlling the delivery amountplunger 9 whilst the other end'of the spring bears through transmissionmeans which are common against-theinner of the two plates 1 which arese- 55- cured to the end of the control rod. The return spring I 5 tendsto push the control rod out of the chamber 6' and thereby to adjust thecontrol rod in the direction of full load.

On the left hand end of the sleeve 9 is mounted a bracket I! whichcarries an adjustable stop l8 against which the outer of the two platesI impinges on reaching the position of full load.

On the outer face of 'the end wall of the plunger is mounted a boss l9to which a lever 20 is connected, the pivot of which is seated on thecasing. The otherv end of this lever is connected to the lid of a member2| which is responsive to variations in atmospheric pressure in themanner of the operating mechanism of a barometer and which is attachedby its bottom base to an arm 22 fixed to-the casing 6. The pivotal axisof the lever 20 is adjustable by means of. an ecposition by the variablepressure member 2|.

If the engine is required to operate at higher altitudes themember 2|expands as atmospheric air pressure sinks. ,In such event the plunger 9moves to the right together with the parts connected with it, thecontrol rod being also displaced a similar distance to the right. on thepneumatic regulator itself no alteration takes place, since the member2| has no influence on the pressure and force conditions in the interiorof the regulating chamber. Owing to this movement of the control rod inthe direction of stop, the amountof fuel delivered to the engine isdiminished by an amount corresponding to the weight of the air drawn in.

Should the engine when the machine is climbing, be adjusted to highperformance by opening the throttle valve, a lower depression occurs inthe induction pipe and in the chamber 9 as a result of the smallthrottling still present. Accordingly the return spring l5 expandsconsiderably and tends to adjust the control rod to the maximum deliveryquantity of the injection pump. With increasing height of climb, thepressure in the chamber 6' and in the control chamber diminishesfurther. These pressures however diminish by differing amounts and infact the unthrottled external air pressure in the chamber 6'will'decrease somewhat more rapidly than the pressure in the chamberwithin the plunger 9, so that the pressure drop of the pneumaticregulator diminishes continually withincreasing height of climb. Thisdecrease however is small, since only a small depression is available inthe inte'rio'r of the chamber 9 and the displacement force of the returnspring is weakened. Nevertheless the return spring can still displacethecontrol rod by a small amount. corresponding to the lessening of thepressure drop, that is towards the full" position, in addition to the,amount by which it has already displaced the control rod following theopening of the- During a climb' under load atthrottle valve. greataltitudes, there occurs through the atmospheric pressure a doublecorrection of the adpump and its plunger 29 is pivotally connectedjustment of the control rod which stands at the full" position; that isto say, there occurs through the member 2| a powerful movement towardsthe stop position whilst as a result of the lowering of the pressuredrop this power- 5 ful movement is-opposed by a weak displacementtowards the full position on the pneumatic regulator. This correctioncorresponds roughly to actual conditions in as far as at equal absolutepressure in the suction pipe at different heights, 10 a somewhat largerquantity of fuel, which the pneumatic regulator automatically adjusts,must be injected as a result of the small counter pressure of theexhaust and the better air fitting connected with it.

In the example illustrated in Fig. 2 a spring 25 is arranged on theguide casing 6 for the movable chamber 9; one end of this spring abutsagainst a lug 26 of the casing 6. The other end of the spring bearsagainst a holder 21 which go is attached to the control rod 4 and ismoved to and fro with it when the control rod under partial load or noload has been drawn to the right due to considerable drop in pressureand also when the control rod with the whole chamber as a unit is movedstill further to the right in the .direction of the "stop position as aresult of low atmospheric pressure, while the machine climbs to aconsiderable altitude. In this period the tension of the spring 25limits increasingly the adjusting force of the member 2| so that thiscannot produce a decrease of the amount injected which is too large orwhich exceeds the set amount.

, The construction according to Fig. 3 differs from those of Figs. 1 and2 in that the member 2| is arranged between the pneumatic regulator andthe control rod. The casing 28 of the pneumatic regulator is secured tothe injection through the piston rod 29' with one end of a lever 39, theother end of which is pivotallyvconnected to the free end of the controlrod 4. .The lid 3| of the member 2| is pivotally connected with thedisplacement lever 24. By means of the flexible pipe III the controlchamber which is closed'externally by the plunger, is in communicationwith the induction pipe I 2 at a part in rear of the throttle valve l3.With unaltering atmospheric pressure the point of connection 3| of thelever 39 with the member 2| does not move. With alterations of thedepression in the induction pipe the control plunger 29 is moved to andfro and its movement is transmitted by the lever 39 to the control rod4. In this case only the small friction forces occurring with movementof the control rod must be overcome. .If the at- .mospheric pressurealters, the point of connection '3l' is'displaced and the lever thencauses at the-same time a displacement of the controlrod: In both casesthe adjusting forces of the pneumatic regulator do not operate on themember 2| and vice versa so that the control operates almost withoutreturn pressure.

As Fig. 3 shows, the base 33-015 the member 2| is mounted movably on thecasing of the injection pump by means of a pin 24. The bifurcated end ofa lever 35 engagesthe pin 34, and is rotatably mounted on apivot 36carried by the casing and is tensioned by a spring 21. 70 By means ofthe lever SS-the member 2| can be moved bodily to and fro through itsadjusting device so that the lever 34 is turned and the control rodalters its position relative to the pneu-v matic regulator. By means ofthis device the 7| amount of fuel injected can be adjustedindepe'nderrtly from the pressure conditions temporarily prevailing onthe member 2| or in the pneumatic regulator. I

The example of construction in Fig. 4 shows a regulating device in whichthe chamber of the pneumatic regulator behind the throttle I3 isconnected to the air inlet |2 of an injection internal combustion engineworking with a compressor or blower G shown diagrammatically.

The lower end of the lever 30 through which the member 2| and themovable control piston of the pneumatic regulator adjust a control rod4, is led into the casing 28' of the pneumatic regulator and connectedto the piston rod 29'. On the" piston rod 29' a support 38 for a returnspring 39 .is secured which abuts against the cover of the casing 28 inwhich the piston rod 29' is mounted. In the position drawn the. returnspring |5 no longer bears on the piston 29 and only the spring 39working in opposed relationship to the spring l5 operates on thispiston.

'This spring 39 tends to displace it to the left against the absolutepressure operating in the control chamber 32.

0n the shaft 36, which according to Fig. 3 is provided for displacingthe member 2|, a lever '40 is secured which is'moved by a thermostat 4|through the medium of a Bowden wire 42, said thermostat being mountedin, any desired location adjacent the fuel pump so as to be sensi- 'tiveto changes in atmospheric temperature.-

With alterations of the atmospheric temperature the thermostat 1 candisplace the member 2| through the Bowden' wire and correct the positionof the control rod by means of the lever 30. When no change intemperature occurs, thermostat '4|, Bowdenwire 42 and lever 40 form, in

effect, afixed stopfor the left hand end of the membrane 2|, so thatwhen changes in atmospheric pressure occur, the membrane capsule 2| bymeans of its movableright hand end, can displace lever 39 and controlrod 4.' It will be obvious that thermostat 4| and membrane capsule 2|can also work simultaneously.

On the shaft is mounted a further lever 43, which is adjustableindependently of the lever 40,

I and which is connected by means of a rod 44 to an adjustment lever 45,adapted to be set by the driver of the engine, for a control member orpivoted vane '46, rotatably disposed or pivotally mounted in theinduction'pipe of the engine.

This control member or valve 46 is arranged between the compressor orblower and the throttle l3. in the induction pipe and is pressed-againstor loosely connected with a boss or abutment member 41 carriedby lever'45, by the load pressure or flow of air in air inlet l2. Control member46 thus constitutes a regulating device ,or

pivoted vane by whichtheflow of air under pres sure from the compressoror blower G can be controlled or regulated. Ordinarily the vane 46 ismaintained in the position shown in full lines in Fig. 4, but if theengineis to be excessively accelerated for-starting and maximum power isdesired, lever 45 and boss 41 will be rotated or moved byhand in thedirection of the arrow in Fig. 4 to move the vane 46 to the'fully openposition shown in dotted lines. When the lever 45 is moved to the rightin the direction of the arrow, a clockwiserotation is transmitted by rod44 to lever 43, which turns leve'r'35 clockwise by means of the stop orabutment member 43.

This right hand movement of lever 45, with consequent movement of leverarms 40 and 43 to the right and lever arm 35 to the left to cause anincrease in the delivery of fuel, takes placeagainst the tension of acomparatively stiff spring 5|), which yields to permit this movement andwhich, under normal working conditions of the thermostat 4| and membrane2|, presses the bell crank lever 5| connected with the Bowdenwlre 42against the top of the thermostat. The spring 50 has such a highpretension that, except when moved as just explained, it acts as-a stopto permit relative movement of the right hand end of membrane -2| tomovelever 30 and control rod 4. When the vane 46 is in the position shown indotted lines in Fig. 4, the blower G can produce a high air pressure inthe induction pipe as well asin the line l0 and in the governor chamberat the left hand side of the movable piston 29 and underthe influence ofsuch high air pressure said piston will ,move'toward the.

right and adjust an excess fuel delivery of the 20 injection pump bydisplacing the control rod 4 accordingly.

When the aeroplane reaches higher altitudes and the air pressure sinks,the blower will deliver, a

prevails on both sides of the control piston, the

piston is in a position in which both the return springs operate on it.-As soon as the load pressure present in the control chamber is greaterthan the external air pressure it displaces the control piston so far tothe right that the return spring I5 ceases to opcrate and only thereturn spring 39 controls or acts on the plate v3B. Corresponding tosmaller deviations of the overload pressure from the .external airpressure, the return spring 39. in so far as its loading action isconcerned becomes weaker than the return spring 1 5, which operates on.depression in the'induction pipe. The load I pressure in the controlchamber, from the moment when'the spring 39 only operates against it,should be such as to further displace the control rod through thecontrol piston in thedirection of increasing the amount of fuel upon anincrease in the load pressure, and "softhat upon a still furtherincrease of the load pressure,

'it will produce a considerable further increase in the quantity of fueldelivered per piston stroke. We declare that what we claim is:

1. -Apparatus for controlling the amount of fuel supplied to internal]combustion engines having an induction pipe and which operate atconstant and also sharply changing atmospheric pressures, conprisingfuel controlling means for varying the amount of fuelsupplied to saidengine, a device sensitive to variations in pressure 'in' said inductionpipe, a device sensitive to variations in atmospheric temperature, adevice sensitive to variations in atmospheric pressure, and mechanismoperatively connecting said devices,

.to said fuel controlling means whereby said means is automaticallycontrolled and actuated jointly by said devices.

2. Apparatus for controlling the amount of fuel supplied to internalcombustion engines operating at constant and also sharply changingatmospheric pressures and having an induction pipe, 8, throttle valvetherein and means for 5 supplying air under pressure to said inductionand said engine, a devicesensitive to variations in atmospherictemperature, a device sensitive to variations inatmospheric pressure,and mechanism operatively connecting said devices to said fuelcontrolling member whereby said member is automatically controlled andactuated jointly by 'said devices.

3 Apparatus for controlling the amount of fuel supplied to internalcombustion engines operating at constant and also sharply changingatmospheric pressures and having an induction pipe, a, throttle valvetherein and means for supplying air under pressure to said inductionpipe, comprising a fuel controlling member for-varying the amount offuel supplied to said engine, a device sensitive to variations inpressure in said induction pipe between said throttle valve and saidengine, a device sensitive to variations in atmospheric temperature, adevice sensitive to variations in atmospheric pressure, mechanismoperatively connecting said devices to said fuel controlling memberwhereby said member is automatically controlled and actuated jointly bysaid devices, and manual means for moving a portion of said mechanismandcausing it to actuate said fuel controlling member. 4. Apparatus forcontrolling the, amount of .fuel: supplied to internal combustionengines having an inductionpipe and operable at varying altitudes,comprising a fuel controlling mem- 49 her for varying the amount of fuelfed to said engine, a device responsive to pressure in said inductionpipe, a lever pivotally connected at one end to said induction pressureresponsive device and at the other end to said controlling member, 45 athermostat pivotally connected to said lever intermediate its ends andacting on said lever and said fuel. controlling member to compensate forthe effect of variations in air temperature, and an atmospheric pressureresponsive device piv- 60 otally connected-to said lever inter-mediateits ends and acting on said lever and said fuel controlling member tocompensate for variations in atmospheric pressure.

5. The combination, with an internal combustion engine of the liquidfuel injection type hav ing an induction pipe, means for supplying airunder pressure to said induction pipe and a throttle valve in saidinduction pipe between the engine and said air-pressure-gsupplyingmeans, of a fuel-supply system and control means therefor adapted tocontrol the speed of theengine according to the position of saidthrottlevalve; said fuel supply system and control means thereforcomprising a fuel injection pumpdriven by said engine, a displaceable'control member, means mounting said control member for movement inopposite directions, said control member being 'movable in oppositedirections by differences in fluid pressure on its opposite faces, meansexposing one face of said control member to atmosphere and its oppositeface to the pressure,

varying from sub-atmospheric to super-atmospheric, in said inductionpipe on the engine side of said throttle valve, means operated by saidcontrol member\ to control the rate of fuel delivery of said pump inaccordance with the displacement -of said control' member, resilientmeans applying a resisting force to said control member to resistmovement thereof in one direction in response to the effect of pressuresless than atmospheric exerted thereon, and opposed resilient meansapplying a resisting force to said control member to resist movementthereof in the opposite direction in response to the eflect of pressuresgreater than atmospheric exerted thereon.

6. The combination as set out in claim 5 including a thermostatconnected to said fuel delivery controlling 'means and acting thereon tocompensate for variations in air temperature,

and an atmospheric pressure responsive device,

connected to said fuel controlling means and acting thereon tocompensate for variations in atmospheric pressure.

'7. The combination as set out in claim 5 including a valve in saidinduction pipe between said air-pressiire-supplying means and saidthrottle valve whereby the flow of air under pressure from saidair-pressure-supplying means can be controlled, a thermostat connectedto said fuel delivery controlling means and acting thereon to compensatefor variations in air temperature, and an atmospheric pressureresponsive device connected to said fuel delivery control- ,ling meansand acting thereon to compensate for variations in atmospheric pressure.7

-8. Apparatus for controlling the amount of fuel supplied to an internalcombustion engine having an induction pipe and a throttle valve. withinsaid induction pipe, comprising, in combination, a pneumatic governorhaving two governor chambers separated one from the other.

metric means pivotally connected to an intermediate point of said doublearmed lever rind providing a movable fulcrum point therefor controlledby said barometric means.

9. Apparatus as set out in claim '7 includingspring tensioned means fornormally supporting said barometric means against movement butpermitting movement thereof against the tension of said spring, andmanual means for moving said spring tensioned means against the tensionof said spring.

ALFRED SCHWEIZER.

MAX HURST.

